View Single Post
Old 11-16-2016, 09:32 AM   #674 (permalink)
Master EcoModder
basjoos's Avatar
Join Date: Dec 2007
Location: Upstate SC
Posts: 1,051

Aerocivic - '92 Honda Civic CX
Last 3: 70.54 mpg (US)

AerocivicLB - '92 Honda Civic CX
Team Honda
90 day: 55.14 mpg (US)
Thanks: 6
Thanked 562 Times in 269 Posts
I made a trip up to the NC mountains a few weeks back and saw the effect that altitude has on mpg. At 400 feet elevation at 55mph, 15" of manifold pressure, and 85 degrees my SuperMID shows 100mpg. At 2100 feet elevation those same parameters show close to 120mpg. The mpg improvement would be due to a combination of reduced aero drag in the thinner air and the 15" of manifold pressure at 2100 feet elevation resulting in a wider open throttle plate for reduced pumping losses. I wonder what it would show at 6000 feet, not that there are any flat, straight road stretches to try this on in the eastern US.
  Reply With Quote
The Following 6 Users Say Thank You to basjoos For This Useful Post:
aerohead (11-19-2016), COcyclist (11-16-2016), Daox (11-16-2016), elhigh (11-16-2016), freebeard (11-16-2016), MetroMPG (02-24-2017)